Improvement in burglar-alarms



R. W. NEWBER Y.

Improvement in Burglar Alarms.

No, 120,313, Patented Oct. 24,1871.

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ROBERT WILLIAM NEWBERY, OF NEW YORK, N. Y.

IMPROVEMENT lN BURGLAR-ALARMS.

Specification forming part of Letters Patent N 0. 120,313, dated October 24, 1871.

To all whom it may concern:

Be it known that I, ROBERT WILLIAM NEW- BERY, of the city of New York, in the county and State of New York, have invented a new and useful Improvement in Burglar-Alarm and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawing forming part of this specification, 'in which Figure 1 represents a face view of my improved burglar-alarm. Fig. 2 is a longitudinal section of the same on the line 0 c, Fig. 1.

Similar letters of reference indi cate corresponding parts.

This invention relates to the application of a detonating cracker to doors and windows, drawers, and other movable devices for the purpose of serving as a burglar-alarm.

The detonating cracker A consists of a cartridge, a, and two strips, 1) b, which overlap each other within the cartridge and extend from the ends of the same, as shown. The explosive matter is placed within the cartridge between or otherwise in contact with the overlapping strips 1) b, so that when the strips are pulled they will by friction cause the firing of the charge and consequent explosion. B is a shield fastened against the back of the cartridge. Its object is to protect the paint of the door, window, or other article to which the alarm is applied and prevent its being defaced or injured by the explosion. The strips 1) and cartridge a should be made of incombustible material, so that the shreds, after explosion, will not set any thing on fire, burn holes into carpets, or do other damage to property. The ends of the strips 1) b are, by tacks, pins, or gum, fastened in place, so that the opening by unauthorized persons of a door, window, lid, or drawer will cause the explosion and alarm.

Having thus described my invention, I claim as new, and desire to secure by Letters Patent- 1. The detonating cracker, furnished with attaching arms or strips, and used as a burglaralarm, substantially as shown and described.

2. The protecting-shield B applied to the cracker, substantially as and for the purpose herein shown and described.

ROBT. WM. NEVVBERY.

Witnesses:

A. V. BRIESEN, 

